Substiotution of tabs with spaces...

Substiotution of tabs with spaces...

[luca.spinacci]

Hi,
is there a smart way to replace all tabs with 3 spaces in a buffer edited
in c-mode
(both comments and code lines)

Thank you very much.

Re: Substiotution of tabs with spaces...

[Peter Dyballa]

Am 15.04.2005 um 11:06 schrieb luca.spinacci@seleniacomms.com:

> is there a smart way to replace all tabs with 3 spaces in a buffer 
> edited
>

How about: replace-regexp RET TAB + RET SPC SPC SPC RET ?
Or: replace-string RET TAB RET SPC SPC SPC RET ?
--
Greetings

   Pete

Got Mole problems?
Call Avogadro 6.02 x 10^23

Re: Substiotution of tabs with spaces...

[Pascal Bourguignon]

Peter Dyballa <Peter_Dyballa@Web.DE> writes:

> Am 15.04.2005 um 11:06 schrieb luca.spinacci@seleniacomms.com:
> 
> > is there a smart way to replace all tabs with 3 spaces in a buffer
> > edited
> >
> 
> How about: replace-regexp RET TAB + RET SPC SPC SPC RET ?
> Or: replace-string RET TAB RET SPC SPC SPC RET ?

It's not satisfactory.  For example, try it on:

(progn
    (find-file "/tmp/exemple")
    (erase-buffer)
    (insert "\n\ta\ta\n\taa\taa\n\taaa\taaa\n"))


Also, with my emacs configuration, 
M-x replace-string RET TAB
tries to substitute a string of four spaces, not one tabulation.

Try:

 M-x replace-regexp RET C-q TAB + RET SPC SPC SPC RET 
 M-x replace-string RET C-q TAB RET SPC SPC SPC RET 

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
You never feed me.
Perhaps I'll sleep on your face.
That will sure show you.

Re: Substiotution of tabs with spaces...

[Peter Dyballa]

Am 15.04.2005 um 15:15 schrieb Pascal Bourguignon:

> Also, with my emacs configuration,
> M-x replace-string RET TAB
> tries to substitute a string of four spaces, not one tabulation.
>
> Try:
>
>  M-x replace-regexp RET C-q TAB + RET SPC SPC SPC RET
>  M-x replace-string RET C-q TAB RET SPC SPC SPC RET
>

Yes, that's something I've seen here too. I remember that I failed a 
few times to remove, i.e. replace-regexp with nothing, [SPC TAB]+$ -- 
there could be a better regexp too. Do have an idea why TAB is 
sometimes \t and sometimes a few spaces?

--
Greetings

   Pete

Re: Substiotution of tabs with spaces...

[Pascal Bourguignon]

Peter Dyballa <Peter_Dyballa@Web.DE> writes:

> Am 15.04.2005 um 15:15 schrieb Pascal Bourguignon:
> 
> > Also, with my emacs configuration,
> > M-x replace-string RET TAB
> > tries to substitute a string of four spaces, not one tabulation.
> >
> > Try:
> >
> >  M-x replace-regexp RET C-q TAB + RET SPC SPC SPC RET
> >  M-x replace-string RET C-q TAB RET SPC SPC SPC RET
> >
> 
> Yes, that's something I've seen here too. I remember that I failed a
> few times to remove, i.e. replace-regexp with nothing, [SPC TAB]+$
> --  there could be a better regexp too. Do have an idea why TAB is
> sometimes \t and sometimes a few spaces?

TAB is TAB, and SPC is SPC.

What happens, is that TAB is a CONTROL character that was used to
CONTROL a mecanical teletype device, to make it move mecanically the
carriage to the next tabulation stop.

Since its meaning depends highly on the device (the width of the
tabulation changes, on some devices there's no tabulation, so it
doesn't show at all or is replaced by one space), and you cannot SEE
whether there is one TAB or several SPC, it should not be used in
normal files.  Use instead only SPC and sequences of SPC.

That's why in emacs, we usually bind the TAB key to more interesting
functions, such as lisp-indent-line or c-ident-command, and these
command indent the current line according to the syntax (using
normaly only spaces).

This has the added benefit that when you visualise the file in a
different environment, it always display correctly indented.


You should have: 
    (setq tab-always-indent t)
in  your ~/.emacs !

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

Nobody can fix the economy.  Nobody can be trusted with their finger
on the button.  Nobody's perfect.  VOTE FOR NOBODY.

Re: Substiotution of tabs with spaces...

[Peter Dyballa]

Am 16.04.2005 um 01:38 schrieb Pascal Bourguignon:

> You should have:
>     (setq tab-always-indent t)
> in  your ~/.emacs !
>

I think that's the default value. In GNU Emacs 22.0.50 and 21.3.50 it 
is t although I never set it.

--
Greetings

   Pete



--
Mit friedvollen Grüßen

   Pete

Macht kaputt, was Afghanistan kaputt macht!

Re: Substiotution of tabs with spaces...

[Stefan Monnier]

> Do have an idea why TAB is sometimes \t and sometimes a few spaces?

This makes no sense.  TAB is TAB and nothing more.
What you probably mean is that the TAB *key* is bound to a command that
doesn't always insert just a TAB character or just spaces, but sometimes
one, sometimes the other, and sometimes something yet different.

Look for Kai's tutorial on TAB and other key bindings.


        Stefan

Re: Substiotution of tabs with spaces...

[Steinar Børmer]

Stefan Monnier wrote:

| Look for Kai's tutorial on TAB and other key bindings.

These can be hard to find, as most of the links I've come across are
dead.  (Kai, are you reading this?)  However, I was able to locate them
on the XEmacs web site:

<URL: http://www.xemacs.org/Links/tutorials_toc.html >

HTH.

-- 
SB

Re: Substiotution of tabs with spaces...

[Peter Dyballa]

Am 17.04.2005 um 22:05 schrieb Steinar Børmer:

> Stefan Monnier wrote:
>
> | Look for Kai's tutorial on TAB and other key bindings.
>
> These can be hard to find, as most of the links I've come across are
> dead.  (Kai, are you reading this?)  However, I was able to locate them
> on the XEmacs web site:
>
> <URL: http://www.xemacs.org/Links/tutorials_toc.html >

Here is a second place to read (could be to download/checkout too):  
http://cvs.sourceforge.net/viewcvs.py/*checkout*/xemacs/xemacsweb/ 
Links/Attic/tutorials_toc.html?content-type=text%2Fplain

--
Greetings

   Pete

Re: Substiotution of tabs with spaces...

[Peter Dyballa]

Am 17.04.2005 um 22:05 schrieb Steinar Børmer:

> <URL: http://www.xemacs.org/Links/tutorials_toc.html >

I think that is the new URL to the tutorials at the University in 
Duisburg: 
ftp://ftp.is.informatik.uni-duisburg.de/pub/src/emacs/tutorials/. I 
found it from the GNUS home page http://my.gnus.org/.

--
Greetings

   Pete

Re: Substiotution of tabs with spaces...

[Steinar Børmer]

Peter Dyballa wrote:

| I think that is the new URL to the tutorials at the University in 
| Duisburg: 
| ftp://ftp.is.informatik.uni-duisburg.de/pub/src/emacs/tutorials/. I 
| found it from the GNUS home page http://my.gnus.org/.

I think a lot of people who don't use Gnus would benefit from reading
these.  Google doesn't find the URL you mention.  Seeing how the XEmacs
community obviously appreciates these, I think GNU Emacs users should
have the same opportunity to read them.

I've added this new URL to the EmacsWiki so that it's at least a bit
more accessible.

<URL: http://www.emacswiki.org/cgi-bin/wiki/OnlineResources >
<URL: http://www.emacswiki.org/cgi-bin/wiki/IndentationTutorial >

-- 
SB

Re: Substiotution of tabs with spaces...

[Quokka]

Peter Dyballa wrote:
> 
> Am 15.04.2005 um 11:06 schrieb luca.spinacci@seleniacomms.com:
> 
>> is there a smart way to replace all tabs with 3 spaces in a buffer edited
>>
> 
> How about: replace-regexp RET TAB + RET SPC SPC SPC RET ?
> Or: replace-string RET TAB RET SPC SPC SPC RET ?

Mark the whole buffer then
M-x untabify RET

OR

(defun untabify-buffer ()
   "Untabifies entire buffer."
   (interactive)
     (save-excursion
          (untabify      (point-min) (point-max))))


Paul

Re: Substiotution of tabs with spaces...

[Pascal Bourguignon]

luca.spinacci@seleniacomms.com writes:

> Hi,
> is there a smart way to replace all tabs with 3 spaces in a buffer edited
> in c-mode
> (both comments and code lines)

C-x h M-| expand -3 RET

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

Nobody can fix the economy.  Nobody can be trusted with their finger
on the button.  Nobody's perfect.  VOTE FOR NOBODY.

Re: Substiotution of tabs with spaces...

[Alan Mackenzie]

luca.spinacci@seleniacomms.com wrote on Fri, 15 Apr 2005 11:06:02 +0200:

> Hi,
> is there a smart way to replace all tabs with 3 spaces in a buffer edited
> in c-mode
> (both comments and code lines)

Yes, but that might not be what you really want.  Assuming you've got
tab-width set to 3, a tab extends to the next column which is a multiple
of 3.  So if you had this in a buffer

a<tab>b

it would look like this:

a  b

If you replaced the tab with three spaces, you'd end up with this

a   b.

I suggest you do this:  C-x h  (to mark the entire buffer) followed by
M-x untabify.

> Thank you very much.

And the best of luck!

-- 
Alan Mackenzie (Munich, Germany)
Email: aacm@muuc.dee; to decode, wherever there is a repeated letter
(like "aa"), remove half of them (leaving, say, "a").